Which of the following is true of graft copolymers?
Group of answer choices
They are composed of two different types of mer: one mer resides on the main chain of the polymer and the other mer resides on a branch off of the main chain.
They are composed of single type of mer that is crosslinked.
They are composed of a single type of mer that is networked in 3-dimensions.
They are composed of two different types of mer: both types of mer are clustered together along the main chain of the polymer.
Answer
Understanding Graft Copolymers
✅ Correct Statement:
They are composed of two different types of mer: one mer resides on the main chain of the polymer and the other mer resides on a branch off of the main chain.
This describes the defining structure of graft copolymers, where a primary polymer backbone (main chain) consists of one type of monomer (mer), and side chains (branches) composed of a different type of monomer are chemically attached to this backbone.
- The backbone provides the linear structure.
- The side chains “graft” a second polymer type onto the first.
- This structure enables the combination of properties from both monomers in a single material.
🚫 Incorrect Statements:
They are composed of single type of mer that is crosslinked.
This describes a crosslinked homopolymer, not a graft copolymer. Crosslinking refers to covalent bonds joining polymer chains into a network, typically from the same monomer.
They are composed of a single type of mer that is networked in 3-dimensions.
This refers to a network polymer or thermoset, which forms a 3D crosslinked structure made from a single type of monomer.
They are composed of two different types of mer: both types of mer are clustered together along the main chain of the polymer.
This describes a random or block copolymer, not a graft copolymer. In block or random copolymers, both monomers are present in the main chain, either randomly distributed or in blocks.